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  <div class="section" id="the-python-language-reference">
<span id="reference-index"></span><h1>Python 语言参考<a class="headerlink" href="#the-python-language-reference" title="永久链接至标题">¶</a></h1>
<p>本参考手册描述了 Python 的语法和“核心语义”。本参考是简洁的，但试图做到准确和完整。 非必要的内建对象类型和内建函数、模块的语义描述在 <a class="reference internal" href="../library/index.html#library-index"><span class="std std-ref">Python 标准库</span></a> 中。有关该语言的非正式介绍，请参阅 <a class="reference internal" href="../tutorial/index.html#tutorial-index"><span class="std std-ref">Python 教程</span></a> 。对 C 或 C++ 程序员，还有两个额外的手册： <a class="reference internal" href="../extending/index.html#extending-index"><span class="std std-ref">扩展和嵌入 Python 解释器</span></a> 概述了如何编写一个 Python 扩展模块，<a class="reference internal" href="../c-api/index.html#c-api-index"><span class="std std-ref">Python/C API 参考手册</span></a> 详细介绍了 C/C++ 中可用的接口。</p>
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<li class="toctree-l1"><a class="reference internal" href="introduction.html">1. 概述</a><ul>
<li class="toctree-l2"><a class="reference internal" href="introduction.html#alternate-implementations">1.1. 其他实现</a></li>
<li class="toctree-l2"><a class="reference internal" href="introduction.html#notation">1.2. 标注</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="lexical_analysis.html">2. 词法分析</a><ul>
<li class="toctree-l2"><a class="reference internal" href="lexical_analysis.html#line-structure">2.1. 行结构</a></li>
<li class="toctree-l2"><a class="reference internal" href="lexical_analysis.html#other-tokens">2.2. 其他形符</a></li>
<li class="toctree-l2"><a class="reference internal" href="lexical_analysis.html#identifiers">2.3. 标识符和关键字</a></li>
<li class="toctree-l2"><a class="reference internal" href="lexical_analysis.html#literals">2.4. 字面值</a></li>
<li class="toctree-l2"><a class="reference internal" href="lexical_analysis.html#operators">2.5. 运算符</a></li>
<li class="toctree-l2"><a class="reference internal" href="lexical_analysis.html#delimiters">2.6. 分隔符</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="datamodel.html">3. 数据模型</a><ul>
<li class="toctree-l2"><a class="reference internal" href="datamodel.html#objects-values-and-types">3.1. 对象、值与类型</a></li>
<li class="toctree-l2"><a class="reference internal" href="datamodel.html#the-standard-type-hierarchy">3.2. 标准类型层级结构</a></li>
<li class="toctree-l2"><a class="reference internal" href="datamodel.html#special-method-names">3.3. 特殊方法名称</a></li>
<li class="toctree-l2"><a class="reference internal" href="datamodel.html#coroutines">3.4. 协程</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="executionmodel.html">4. 执行模型</a><ul>
<li class="toctree-l2"><a class="reference internal" href="executionmodel.html#structure-of-a-program">4.1. 程序的结构</a></li>
<li class="toctree-l2"><a class="reference internal" href="executionmodel.html#naming-and-binding">4.2. 命名与绑定</a></li>
<li class="toctree-l2"><a class="reference internal" href="executionmodel.html#exceptions">4.3. 异常</a></li>
</ul>
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<li class="toctree-l1"><a class="reference internal" href="import.html">5. 导入系统</a><ul>
<li class="toctree-l2"><a class="reference internal" href="import.html#importlib">5.1. <code class="docutils literal notranslate"><span class="pre">importlib</span></code></a></li>
<li class="toctree-l2"><a class="reference internal" href="import.html#packages">5.2. 包</a></li>
<li class="toctree-l2"><a class="reference internal" href="import.html#searching">5.3. 搜索</a></li>
<li class="toctree-l2"><a class="reference internal" href="import.html#loading">5.4. 加载</a></li>
<li class="toctree-l2"><a class="reference internal" href="import.html#the-path-based-finder">5.5. 基于路径的查找器</a></li>
<li class="toctree-l2"><a class="reference internal" href="import.html#replacing-the-standard-import-system">5.6. 替换标准导入系统</a></li>
<li class="toctree-l2"><a class="reference internal" href="import.html#special-considerations-for-main">5.7. 有关 __main__ 的特殊事项</a></li>
<li class="toctree-l2"><a class="reference internal" href="import.html#open-issues">5.8. 开放问题项</a></li>
<li class="toctree-l2"><a class="reference internal" href="import.html#references">5.9. 参考文献</a></li>
</ul>
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<li class="toctree-l1"><a class="reference internal" href="expressions.html">6. 表达式</a><ul>
<li class="toctree-l2"><a class="reference internal" href="expressions.html#arithmetic-conversions">6.1. 算术转换</a></li>
<li class="toctree-l2"><a class="reference internal" href="expressions.html#atoms">6.2. 原子</a></li>
<li class="toctree-l2"><a class="reference internal" href="expressions.html#primaries">6.3. 原型</a></li>
<li class="toctree-l2"><a class="reference internal" href="expressions.html#await-expression">6.4. await 表达式</a></li>
<li class="toctree-l2"><a class="reference internal" href="expressions.html#the-power-operator">6.5. 幂运算符</a></li>
<li class="toctree-l2"><a class="reference internal" href="expressions.html#unary-arithmetic-and-bitwise-operations">6.6. 一元算术和位运算</a></li>
<li class="toctree-l2"><a class="reference internal" href="expressions.html#binary-arithmetic-operations">6.7. 二元算术运算符</a></li>
<li class="toctree-l2"><a class="reference internal" href="expressions.html#shifting-operations">6.8. 移位运算</a></li>
<li class="toctree-l2"><a class="reference internal" href="expressions.html#binary-bitwise-operations">6.9. 二元位运算</a></li>
<li class="toctree-l2"><a class="reference internal" href="expressions.html#comparisons">6.10. 比较运算</a></li>
<li class="toctree-l2"><a class="reference internal" href="expressions.html#boolean-operations">6.11. 布尔运算</a></li>
<li class="toctree-l2"><a class="reference internal" href="expressions.html#conditional-expressions">6.12. 条件表达式</a></li>
<li class="toctree-l2"><a class="reference internal" href="expressions.html#lambda">6.13. lambda 表达式</a></li>
<li class="toctree-l2"><a class="reference internal" href="expressions.html#expression-lists">6.14. 表达式列表</a></li>
<li class="toctree-l2"><a class="reference internal" href="expressions.html#evaluation-order">6.15. 求值顺序</a></li>
<li class="toctree-l2"><a class="reference internal" href="expressions.html#operator-precedence">6.16. 运算符优先级</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="simple_stmts.html">7. 简单语句</a><ul>
<li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#expression-statements">7.1. 表达式语句</a></li>
<li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#assignment-statements">7.2. 赋值语句</a></li>
<li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-assert-statement">7.3. <code class="xref std std-keyword docutils literal notranslate"><span class="pre">assert</span></code> 语句</a></li>
<li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-pass-statement">7.4. <code class="xref std std-keyword docutils literal notranslate"><span class="pre">pass</span></code> 语句</a></li>
<li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-del-statement">7.5. <code class="xref std std-keyword docutils literal notranslate"><span class="pre">del</span></code> 语句</a></li>
<li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-return-statement">7.6. <code class="xref std std-keyword docutils literal notranslate"><span class="pre">return</span></code> 语句</a></li>
<li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-yield-statement">7.7. <code class="xref std std-keyword docutils literal notranslate"><span class="pre">yield</span></code> 语句</a></li>
<li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-raise-statement">7.8. <code class="xref std std-keyword docutils literal notranslate"><span class="pre">raise</span></code> 语句</a></li>
<li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-break-statement">7.9. <code class="xref std std-keyword docutils literal notranslate"><span class="pre">break</span></code> 语句</a></li>
<li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-continue-statement">7.10. <code class="xref std std-keyword docutils literal notranslate"><span class="pre">continue</span></code> 语句</a></li>
<li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-import-statement">7.11. <code class="xref std std-keyword docutils literal notranslate"><span class="pre">import</span></code> 语句</a></li>
<li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-global-statement">7.12. <code class="xref std std-keyword docutils literal notranslate"><span class="pre">global</span></code> 语句</a></li>
<li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-nonlocal-statement">7.13. <code class="xref std std-keyword docutils literal notranslate"><span class="pre">nonlocal</span></code> 语句</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="compound_stmts.html">8. 复合语句</a><ul>
<li class="toctree-l2"><a class="reference internal" href="compound_stmts.html#the-if-statement">8.1. <code class="xref std std-keyword docutils literal notranslate"><span class="pre">if</span></code> 语句</a></li>
<li class="toctree-l2"><a class="reference internal" href="compound_stmts.html#the-while-statement">8.2. <code class="xref std std-keyword docutils literal notranslate"><span class="pre">while</span></code> 语句</a></li>
<li class="toctree-l2"><a class="reference internal" href="compound_stmts.html#the-for-statement">8.3. <code class="xref std std-keyword docutils literal notranslate"><span class="pre">for</span></code> 语句</a></li>
<li class="toctree-l2"><a class="reference internal" href="compound_stmts.html#the-try-statement">8.4. <code class="xref std std-keyword docutils literal notranslate"><span class="pre">try</span></code> 语句</a></li>
<li class="toctree-l2"><a class="reference internal" href="compound_stmts.html#the-with-statement">8.5. <code class="xref std std-keyword docutils literal notranslate"><span class="pre">with</span></code> 语句</a></li>
<li class="toctree-l2"><a class="reference internal" href="compound_stmts.html#function-definitions">8.6. 函数定义</a></li>
<li class="toctree-l2"><a class="reference internal" href="compound_stmts.html#class-definitions">8.7. 类定义</a></li>
<li class="toctree-l2"><a class="reference internal" href="compound_stmts.html#coroutines">8.8. 协程</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="toplevel_components.html">9. 最高层级组件</a><ul>
<li class="toctree-l2"><a class="reference internal" href="toplevel_components.html#complete-python-programs">9.1. 完整的 Python 程序</a></li>
<li class="toctree-l2"><a class="reference internal" href="toplevel_components.html#file-input">9.2. 文件输入</a></li>
<li class="toctree-l2"><a class="reference internal" href="toplevel_components.html#interactive-input">9.3. 交互式输入</a></li>
<li class="toctree-l2"><a class="reference internal" href="toplevel_components.html#expression-input">9.4. 表达式输入</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="grammar.html">10. 完整的语法规范</a></li>
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